Kopprasch is divided in two books (at least my version...)
It's a very old book but full of useful things, unfortunately there
isn't a single word on how to study them and you really need
someone who can give you some advice! (me? ehehehe)
Each piece deals with a different tecnique and for this reason
you'll never find it boring to study, I myself spend a lot of time
on them and I found them very useful mainly for staccato and
stamina.
UPDATE:
There are 60 exercises and I have just now (october, 2006) recorded
them all again from scratch. Now they are much better, enjoy!
CLICK HERE to
get the files!